Drought is a condition of moisture deficit sufficient to have an adverse
effect on vegetation, animals, and man over a sizeable area

A drought is defined as "a period of abnormally dry weather sufficiently
prolonged for the lack of water to cause serious hydrologic imbalance in
the affected area." -Glossary of Meteorology (1959).

In easier to understand terms, a drought is a period of unusually
persistent dry weather that persists long enough to cause serious
problems such as crop damage and/or water supply shortages. The severity
of the drought depends upon the degree of moisture deficiency, the
duration, and the size of the affected area.

There are actually four different
ways that drought can be defined.

Meteorological-a measure of departure of precipitation from normal.
Due to climatic differences, what might be considered a drought in one
location of the country may not be a drought in another location.

Agricultural-refers to a situation where the amount of moisture in
the soil no longer meets the needs of a particular crop. This condition can
arise, even in times of average precipitation, owing to soil conditions or
agricultural techniques.

Hydrological-is brought about when the water reserves available in
sources such as aquifers, lakes, and reservoirs falls below the statistical
average. This condition can arise, even in times of average (or above
average) precipitation, when increased usage of water diminishes the
reserves.

Socioeconomic-refers to the situation that occurs when physical
water shortages begin to affect people.

While much of the weather that we experience is brief and short-lived,
drought is a more gradual phenomenon, slowly taking hold of an area and
tightening its grip with time. In severe cases, drought can last for
many years, and can have devastating effects on agriculture and water
supplies.

According to United Nations estimates, one third of the world's
population lives in areas with water shortages and 1.1 billion people
lack access to safe drinking water and 2.6 billion people are without
adequate water for sanitation. Consequently disease and significant
deaths arise from people using contaminated water supplies; these
effects are particularly pronounced for children in underdeveloped
countries, where 3900 children per day die of diarrhea alone

Climate change has also provoked more frequent and intense droughts in
sub-tropical areas of Asia and Africa, exacerbating shortages in some of
the world's poorest countries. According to a UN climate report, the
Himalayan glaciers that are the sources of Asia's biggest rivers -
Ganges, Indus, Brahmaputra, Yangtze, Mekong, Salween and Yellow - could
disappear by 2035 as temperatures rise.

While the world's population tripled in the 20th century, the use of
renewable water resources has grown six-fold. Within the next fifty
years, the world population will increase by another 40 to 50 %. This
population growth - coupled with industrialization and urbanization -
will result in an increasing demand for water and will have serious
consequences on the environment.

Water
Resources

The total
volume of water on Earth is about 1.4 billion km3. The volume of
freshwater resources is around 35 million km3, or about 2.5 percent of the
total volume.Source: United Nations Environment Programme
(UNEP)

Of these freshwater resources, about 24 million km3 or 70 percent is in
the form of ice and permanent snow cover in mountainous regions, the
Antarctic and Arctic regions.Source: UNEP

Around 30 percent of the world's freshwater is stored underground in the
form of groundwater (shallow and deep groundwater basins up to 2 000
metres, soil moisture, swamp water and permafrost). This constitutes about
97 percent of all the freshwater that is potentially available for human
use.Source: UNEP

Freshwater lakes and rivers contain an estimated 105 000 km3 or around 0.3
percent of the world's freshwater.Source: UNEP

The Earth's atmosphere contains approximately 13,000 km3 of water.Source: World Water Assessment Programme (WWAP)

The total usable freshwater supply for ecosystems and humans is about 200
000 km3 of water - less than 1 percent of all freshwater resources.Source: UNEP

Water Uses

How the world
uses freshwater:
• about 70 percent for irrigation
• about 22 percent for industry
• about 8 percent for domestic useSource: World Water Assessment Programme (WWAP)

Water use has been growing at more than the rate twice of population
increase in the last century.Source: Food and Agriculture Organization of
the United Nations (FAO) and UN-Water

The world's six billion people are appropriating 54 percent of all the
accessible freshwater contained in rivers, lakes and underground aquifers.
Source: WWAP

145 nations have territory within a transboundary basin.Source: WWAP

Water
withdrawals are predicted to increase by 50 percent by 2025 in developing
countries, and 18 per cent in developed countries.Source: Global Environment Outlook: environment
for development (GEO-4)

Over 1.4 billion people currently live in river basins where the use of
water exceeds minimum recharge levels, leading to the desiccation of
rivers and depletion of groundwater.Source: Human Development Report 2006

In 60 percent of European cities with more than 100,000 people,
groundwater is being used at a faster rate than it can be replenished.Source: World Business Counicl For Sustainable
Development (WBCSD)

By 2025, 1.8 billion people will be living in countries or regions with
absolute water scarcity, and two-thirds of the world population could be
under stress conditions.Source: FAO

Drinking Water
and Sanitation

Today 2.5
billion people, including almost one billion children, live without even
basic sanitation. Every 20 seconds, a child dies as a result of poor
sanitation. That's 1.5 million preventable deaths each year.Source: Water Supply and Sanitation
Collaborative Council (WSSCC)

In Sub-Saharan Africa, treating diarrhoea consumes 12 percent of the
health budget. On a typical day, more than half the hospital beds in are
occupied by patients suffering from faecal-related disease.Source: WSSCC

Washing hands with soap can reduce the risk of diarrhoeal diseases by up
to 47 per cent.Source: WHO

Projected Water Scarcity in 2025

By 2025, 1.8 billion people will live in countries or regions with absolute
water scarcity. Most countries in the Middle East and North Africa can be
classified as having absolute water scarcity today. By 2025, these countries
will be joined by Pakistan, South Africa, and large parts of India and China.
This means that they will not have sufficient water resources to maintain their
current level of per capita food production from irrigated agriculture—even at
high levels of irrigation efficiency—and also to meet reasonable water needs for
domestic, industrial, and environmental purposes. To sustain their needs, water
will have to be transferred out of agriculture into other sectors, making these
countries or regions increasingly dependent on imported food.

Many African countries, with a population of nearly 200 million people, are
facing serious water shortages. By the year 2025, it is estimated that nearly
230 million Africans will be facing water scarcity, and 460 million will live in
water-stressed countries

Credit: NOAA, The National Weather Service, The United Nations, National Drought
Mitigation Center University of Nebraska-Lincoln,UN,WMO

Data compiled from The
British Antarctic Study, NASA, Environment Canada, UNEP, EPA and
other sources as stated and credited Researched by Charles
Welch-Updated daily This Website is a project of the The Ozooe Hole
Inc. http://www.theozonehole.com